Truss



(No Model.)-

P. PRBDIN.

TRUSS.

Patented Nov. 24, 1896.

. Pnmauwo.. wAsmnafoM, nA a UNTTEU STATES PATENT Critics.

PERJOHAN FREDIN, OF NEWY HAVEN, CONN'CTICUT.

VTFUSS.

SPECIFICATION forming part of Letters Patent No. 571,969, dated November 24, 1896.

Application filed April 20, 1896.

To all whom, t may concern:

Be it known that I, PERJoHAN FREDIN, of New Haven, in the county of New Haven and State of Connecticut, have invented a new Improvementin Trusses; and I do hereby declare the following, when taken in connection with the accompanying drawings and the let ters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specication, and represent, in

Figure l, a side view of a truss embodying' my invention; Fig. 2, a top view of the same; Fig. 3, a vertical section; Fig. 4, a side view of the pad detached; Fig. 5, an enlarged view of the outer end of the inflation-tube; Fig. 6, a side view of an auxiliary pad.

rlhis invention relates to an improvement in trusses, and particularly to that class in which the pad consists of an inflated ball, and is an improvement on the invention for which Letters Patent No. 504,158 were issued to me August 29,' 1898.

In many cases it is desirable that the pad should be depressed in the center, so as to form substantially a ring-like pad, and one object of this invention is to provide an inatable pad which may have this feature.

Another object is to combine a pad having a depressed center with an auxiliary pad, so as to form a substantial support in the center of the pad; and the invention consists in certain details of construction and combinations of parts, as will be hereinafter described, and particularly recited in the claims.

As in my previous patent, the truss consists of a cup-shaped frame A, preferably formed of metal and constructed with perforations A. The pad consists of an inflatable ball B, having a small inliation-tube B', by means of which the pad is kept inflated to the required degree. The interior end of this tube B is provided with an internally-threaded sleeve C.

D is a headed screw adapted to be turned into the sleeve C and is formed below its head with a iaring flange E, adapted to pass outside of the tube B, and so that as the screw is turned into the sleeve C the flange E will pass outside of the tube B', which forms a packing between the said iiange and sleeve to eifectually close the end of the tube.

Serial No. 588,219. (No model.)

The pad is formed with central perforations in its upper and lower sides through which a screw F, having a head G, may eX- tend,its upper end projecting above the frame A.v Over the projecting end of the screw F is placed one end of a supportingspring H, which is secured by a nut I, turned onto the screw F, which not only clamps the spring H in position, but also the two sides of the pad between the head and the frame, so as to form a tight joint at that point. The outer end of the spring H is formed with a slot J, through which a pivot extends to connect the spring with the usual belt, (not shown,) and it is also provided with a series of openings K, through which screws may extend into the belt for adjusting the pad in position. A setscrew L is also passed through the outer end of the spring H to take a bearing upon the upper face of the frame, by means of which the frame may be tilted with relation to the spring. By thus connecting the upper and lower edges of the pad it takes the form substantially of a ring.

In case it is desired to have a central support I provide an auxiliary pad llI independent of-the truss-pad, as shown in Fig. 6, which consists of a cylindrical block of rubber having rounded ends and contracted at its central portion. Preferably the block will be provided with a vertical opening a and transverse openings b, more or less in number, and crossing the opening c so as to permit a circulation of air through the ends of the pad. This auxiliary pad is applied to the pad B by inserting one end into the center of the `pad where it will be frictionally held in position.

I am aware that pads have been recessed in the center to form a ring-like face, and I do not therefore wish to be understood as claiming, broadly, such as my invention 5 but,

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. A truss having an inflatable ball-pad furnished with an inflation-tube, a cup-shaped frame adapted to receive said pad, a headed screw extending through the center of said pad and frame, and so as to clamp the central portions of the pad to the inside of the frame, and a nut applied to the outer end of said screw, substantially as described.

IOO

2. In a truss, the combination with a cupshaped frame, 0f an inflatable ball-pad provided With an inflation-tube, and a clamping device extending through the center of said pad and into the frame, and whereby a centrai recess is formed in the pad, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

PERJOHAN FREDIN. Witnesses:

JULIUs TWIss, LILLIAN D. KELSEY. 

